In the manufacture of bicycles, it has been common to utilize tubing of various diameters and to weld or otherwise connect the sections of tubing to form the frame of the bicycle. In more expensive bicycles, it is common to shape the length of tubing at various points along the frame to produce varying diameters or to flatten portions of the frame for clearance purposes and the like. In addition, it has been common to utilize couplings between lengths of tubings. Each of these types of construction not only adds to the weight and cost, but greatly complicates the manufacture of the bicycles.
In another type of bicycle, such as shown in U.S. Pat. Nos. 2,595,075, 3,226,132, 547,734 and 2,187,020, it has been suggested that the frame of the bicycles may be made by utilizing pairs of frames made of a tubing and thereafter welding or clamping the seat mast and fork tube thereto. In each of these types of bicycles, the aforementioned deficiencies in terms of cost and difficulty in manufacture are also found.
Among the objects of the invention are to provide a bicycle and a method for making a bicycle wherein the frame is manufactured at low cost, with minimum operations, has a high strength and low weight, which utilizs a novel dropout structure for connecting the wheels to the frame, which minimizes the problem of varying sizes, and which has a novel disconnectable or breakaway fork assembly.